THE IRKIGATION AGE. 137 



not unreasonable to expect that where there is a deficiency of water in 

 the soil, the small grains may be sown in narrow strips of 4 to 6 drill 

 rows, 9 inches apart, separated by naked strips 30 inches wide, which 

 may be cultivated to yield up their moisture and developed nitrates to 

 the growing grain on either side, and thus mature heavier crops of 

 well-filled grain than would be possible if the seeds were scattered 

 evenly over the whole surface and on the lighter soils in humid cli- 

 mates none of which could be cultivated. 



Such a practice as is here suggested is manifestly summer fallow- 

 ing, but in a very different way, and for quite a distinct purpose, from 

 that usually had in mind. Of course, it would not be urged, except on 

 soil and in climates in which there is an insufficient supply of soil 

 moisture to mature the crop under ordinary methods of handling. The 

 method, however, had a rational basis for sub-humid climates and for 

 the lighter soils of small water capacity in the more humid climates; 

 but it cannot be hoped that it will, under these conditions, give as 

 large yields per acre when figured upon the whole area as the close 

 planting on the soils better supplied with soil moisture. Neither can 

 it be expected that crops can be raised as cheaply by this method as 

 by the ordinary methods. All that can be asserted, or can be reason- 

 ably expected, is that better crops can be raised by it in sub humid 

 climates, than can be raised by the ordinary methods. It is not an 

 easy matter to adapt the method either to growing hay or to maintain- 

 ing pastures of the ordinary sort. 



Tillage to conserve soil moisture, like water for irrigation, can- 

 not be applied except at an increased cost of production. Hence, to 

 cultivate a field where there is nothing to be gained from it is to be 

 avoided. In the early part of the growing season, when the soil is so 

 fully charged with moisture that a small rain easily causes the soil 

 granules to coalesce and destroy the effectiveness of mulches, it is of- 

 ten desirable to repeat the cultivation or harrowing as often as there 

 has been a shower of sufficient intensity to establish good capillary 

 connection between the stirred and unstirred soil. 



It is often of the greatest importance that this re-establishment of 

 the mulch should take place at the earliest possible moment, not only 

 because of the rapid loss of water from wet surfaces, but because of 

 the fact that, when the surface soil has reached a certain degree of 

 dryness while the deeper soil is yet wet, the moisture of the surface 

 layer so strengthens the upward movement or soil moisture into that 

 layer that not only is all of the rain held at the surface, but a very 

 considerable amount of the deeper soil water is brought there also. 

 Our studies have proved, both by observation and by repeated experi- 

 ment, that wetting the surface of the ground may leave the deeper 

 soil actually dryer than it was before, and if the new mulch is not 

 early developed the rain may leave the surface four feet dryer than it 

 would have been had the rain not occurred. 



